I. Field
This disclosure relates to data communication, and in particular, to a novel and improved web farm data synchronization system.
II. Background
Web farms are integral to high-volume web sites because they increase the availability of web sites by distributing processing tasks among several web farm “members.”
FIG. 1 is a schematic diagram of a prior art web farm 100 including members 1 . . . n. Each member is configured to function as a web server as is known in the art and may include a processor 102 and a database 104 for the storage and retrieval of data.
One challenge in implementing a web farm is ensuring that data files are synchronized among all members of the web farm. Typically, new data is presented simultaneously to all members of the web farm 100 through a gateway 106. For the web site to function effectively, data that is presented to the web farm must be stored within the individual members such that data integrity is maintained from member to member. For example, if the new data presented to the web farm represents a new customer to be stored in customer database, all members of the web farm must store the new customer data prior to a new transaction occurring. If any member of the web farm fails to store the new data, the integrity of any future transactions may be compromised.
The prior art has recognized the importance of data synchronization and made attempts to ensure the integrity of distributed data. For example, prior art web farms may employ a time delay to allow all members of the web farm to catch up and store the new data. However, this approach has certain disadvantages. Such a time delay necessarily imposes a limitation on the availability of the individual members of the web farm, and thus the availability of the hosted web site as whole. Furthermore, during the time delay, the new data is being stored on some members of the web farm, while the other members are catching up. Thus, the web farm is not synchronized during the time period. Should at least one of the members fail to synchronize the new data, the web farm may need to be rolled back, a process whereby the data is restored on the members to a previous known state. Rolling back a web farm is an undesirable procedure that is tedious and potentially error-prone.